Right! I think a lot of people, who have not done a lot of "things you can kick" engineering, have a very romantic view of it. Especially the relationship with whoever is nominally setting the goals of the project.

The physics works perfectly, of course. But physics is only a third of the constraint in engineering. The other two thirds are project goals and convention.

Project goals are horribly underspecified, every time. It's incredibly rare to be given a project that is completely constrained on that side, and if you do get one, most of the time it's physically impossible to achieve. This is because the people who write those specifications not doing engineering, they're doing marketing or sales or just had a cool idea. Sometimes that can even be the engineer themselves :-) So it's up to the engineer to fill in the gap, and they do it with experience and a sense of aesthetics, of sorts.

Convention is what constrains the physical possibilities of engineering to the practical. Yes, you can build anything and make it work, possibly even better than what everyone else builds. But you will have to invent and construct a lot of new technologies before you can build your perfect mousetrap. So, you settle on standard components and build a decent one instead. But this introduces a gap between physics and engineering, too. A bit of no-man's land that you can reach into to produce truly great results. But it's up to the engineer to know when it's worth it.